Gas diffusion layer (GDL), as an important component of membrane electrode in proton exchange membrane fuel cell, has a complex gas-liquid two-phase mass transfer process. The accuracy of its reconstruction results has an important impact on the simulation of fuel cell. Aiming at the problem of insufficient reconstruction accuracy of GDL, this study systematically explored the coupling effect of carbon fiber skeleton porosity, structural unit size and binder addition, as well as the influence mechanism of PTFE distribution on vertical plane porosity. By comparing the binder addition results of carbon fiber skeleton with different porosity, the quantitative relationship curve between the porosity of non hydrophobic GDL and carbon fiber skeleton, binder ratio and other parameters was established; Furthermore, the structure-activity relationship of PTFE addition ratio, relative thickness and porosity distribution was analyzed by normalization method. Based on the above research, a step-by-step controllable reconstruction method of GDL based on the assumption of uneven distribution of PTFE is proposed. Compared with the traditional method, the reconstructed GDL is significantly optimized in terms of porosity, pore size distribution and mass transfer performance, which provides a new means to realize the structural control of gas diffusion layer, such as hydrophilicity, hydrophobicity and porosity.
 

Gas diffusion layer, Reconstruction, PTFE, Porosity